Researchers using systematic review and meta-analysis in a randomized controlled trial suggest that the dose-dependent effects of aspirin result in preeclampsia prevention and fetal growth restriction during early pregnancy.
Preeclampsia (PE) is a multisystem disorder that complicates pregnancies, and both pre-eclampsia and fetal growth restriction (FGR) pose a heavy burden on fetal and maternal health and pose the potential to disrupt pregnancy outcome. In the mother, preeclampsia may cause premature cardiovascular disease later in life, such as chronic hypertension and stroke, while children born after preeclamptic pregnancies and who are relatively small at birth have an increased risk of stroke and coronary heart disease in adult life. Preeclampsia has a complex pathophysiology, with the primary cause being abnormal placentation associated with events taking place in the first trimester of pregnancy.
Based on existing research studies on PE and FGR etiology, Roberge et al. (2017) published a novel study in the American Journal of Obstetrics and Gynaecology., They surveyed randomized controlled trials (RCTs) to determine the phase of pregnancy at which the optimal dosage of aspirin should be introduced to reduce the risk of preeclampsia. The methods used during the study were systematic review and meta-analysis. The current research analyzed 45 studies which included 20,909 pregnant women. Women received aspirin or a placebo (or no treatment) starting at ≤ 16 weeks or > 16 weeks. Women who began taking aspirin ≤ 16 weeks displayed lower risk or preeclampsia and fetal growth restriction than those who began taking aspirin > 16 weeks. They also found that the greater the dose, the greater the decrease in risk at ≤16 weeks of gestation.
These findings were in agreement with previous studies, and hence provide the evidence that the effects of aspirin on the prevention of PE and FGR are dose-dependent and optimal when initiated ≤16 weeks of gestation in high-risk women. The limitations of the study include the small groups of RCTs that could make the study biased, making the optimal dose of aspirin difficult to determine. More studies are needed to be done in order to determine the mechanism by which aspirin acts to prevent PE and FGR.
Written By: Nupur Srivastava, PhD